Recently Sony Vegas Platinum has been unable to load files, telling me that "an exception has occured" and then closing down. Is anyone familiar with this error, and how to circumvent it?

I can't retreat to a previous save because it seems to make the entire file inoperable - even if I open different copied versions of the file, I receive an error.

The only thing that's different on this particular project from any others that I've used is that I have .AVI files generated in CamStudio in the video track, but these have been inserted and edited without difficulty so I don't think that that's the issue - this error seems to pop up randomly.